Mylites 2 Mylar Sleeves for Sheet Music & Large Magazines 9-1/2" x 12-1/2" - Pack of 50! At 2-Mil, these are the twice as thick as regular Mylites! Resistant to aging, decomposition, moisture, oxygen, and gas penetration. Not affected by fungus, mold, or mildew. Immune to insect and rodent attack. The fold-over flap can be tucked in or taped closed. Measures 9-1/2" x 12-1/2". Sold in package of 50.